QwtSlider man page

QwtSlider —

The Slider Widget.

Synopsis

#include <qwt_slider.h>

Inherits QwtAbstractSlider, and QwtAbstractScale.

Public Types

enum BGSTYLE { BgTrough = 0x1, BgSlot = 0x2, BgBoth = BgTrough | BgSlot }

enum ScalePos { NoScale, LeftScale, RightScale, TopScale, BottomScale }

enum ScrollMode { ScrNone, ScrMouse, ScrTimer, ScrDirect, ScrPage }

Public Slots

virtual void fitValue (double val)

virtual void incValue (int steps)

virtual void setReadOnly (bool)

virtual void setValue (double val)

Signals

void sliderMoved (double value)

void sliderPressed ()

void sliderReleased ()

void valueChanged (double value)

Public Member Functions

bool autoScale () const

BGSTYLE bgStyle () const

int borderWidth () const

virtual void incPages (int)

bool isReadOnly () const

bool isValid () const

virtual double mass () const

double maxValue () const

virtual QSize minimumSizeHint () const

double minValue () const

Qt::Orientation orientation () const

int pageSize () const

bool periodic () const

QwtSlider (QWidget *parent, Qt::Orientation=Qt::Horizontal, ScalePos=NoScale, BGSTYLE bgStyle=BgTrough)

const QwtScaleDraw * scaleDraw () const

const QwtScaleEngine * scaleEngine () const

QwtScaleEngine * scaleEngine ()

const QwtScaleMap & scaleMap () const

int scaleMaxMajor () const

int scaleMaxMinor () const

ScalePos scalePosition () const

void setAutoScale ()

void setBgStyle (BGSTYLE)

void setBorderWidth (int bw)

void setMargins (int x, int y)

virtual void setMass (double val)

virtual void setOrientation (Qt::Orientation)

void setPeriodic (bool tf)

void setRange (double vmin, double vmax, double vstep=0.0, int pagesize=1)

void setScale (double vmin, double vmax, double step=0.0)

void setScale (const QwtScaleDiv &s)

void setScale (const QwtDoubleInterval &, double step=0.0)

void setScaleDraw (QwtScaleDraw *)

void setScaleEngine (QwtScaleEngine *)

void setScaleMaxMajor (int ticks)

void setScaleMaxMinor (int ticks)

void setScalePosition (ScalePos s)

void setStep (double)

void setThumbLength (int l)

void setThumbWidth (int w)

void setTracking (bool enable)

void setUpdateTime (int t)

void setValid (bool valid)

virtual QSize sizeHint () const

double step () const

void stopMoving ()

int thumbLength () const

int thumbWidth () const

double value () const

Protected Member Functions

const QwtAbstractScaleDraw * abstractScaleDraw () const

QwtAbstractScaleDraw * abstractScaleDraw ()

void draw (QPainter *p, const QRect &update_rect)

virtual void drawSlider (QPainter *p, const QRect &r)

virtual void drawThumb (QPainter *p, const QRect &, int pos)

double exactPrevValue () const

double exactValue () const

virtual void fontChange (const QFont &oldFont)

virtual void getScrollMode (const QPoint &p, int &scrollMode, int &direction)

virtual double getValue (const QPoint &p)

virtual void keyPressEvent (QKeyEvent *e)

void layoutSlider (bool update=true)

virtual void mouseMoveEvent (QMouseEvent *e)

double mouseOffset () const

virtual void mousePressEvent (QMouseEvent *e)

virtual void mouseReleaseEvent (QMouseEvent *e)

virtual void paintEvent (QPaintEvent *e)

double prevValue () const

virtual void rangeChange ()

void rescale (double vmin, double vmax, double step=0.0)

virtual void resizeEvent (QResizeEvent *e)

virtual void scaleChange ()

QwtScaleDraw * scaleDraw ()

int scrollMode () const

void setAbstractScaleDraw (QwtAbstractScaleDraw *)

void setMouseOffset (double)

virtual void setPosition (const QPoint &)

virtual void stepChange ()

virtual void timerEvent (QTimerEvent *e)

virtual void valueChange ()

virtual void wheelEvent (QWheelEvent *e)

int xyPosition (double v) const

Detailed Description

The Slider Widget.

QwtSlider is a slider widget which operates on an interval of type double. QwtSlider supports different layouts as well as a scale.

See also:

QwtAbstractSlider and QwtAbstractScale for the descriptions of the inherited members.

Member Enumeration Documentation

enum QwtSlider::BGSTYLE Background style.

See also:

QwtSlider()

enum QwtSlider::ScalePos Scale position. QwtSlider tries to enforce valid combinations of its orientation and scale position

·
Qt::Horizonal combines with NoScale, TopScale and BottomScale
·
Qt::Vertical combines with NoScale, LeftScale and RightScale

See also:

QwtSlider()

enum QwtAbstractSlider::ScrollMode [inherited] Scroll mode

See also:

getScrollMode()

Constructor & Destructor Documentation

QwtSlider::QwtSlider (QWidget *parent, Qt::Orientationorientation = Qt::Horizontal, ScalePosscalePos = NoScale, BGSTYLEbgStyle = BgTrough) [explicit]

Constructor. Parameters:

parent parent widget
orientation Orientation of the slider. Can be Qt::Horizontal or Qt::Vertical. Defaults to Qt::Horizontal.
scalePos Position of the scale. Defaults to QwtSlider::NoScale.
bgStyle Background style. QwtSlider::BgTrough draws the slider button in a trough, QwtSlider::BgSlot draws a slot underneath the button. An or-combination of both may also be used. The default is QwtSlider::BgTrough.

QwtSlider enforces valid combinations of its orientation and scale position. If the combination is invalid, the scale position will be set to NoScale. Valid combinations are:

·
Qt::Horizonal with NoScale, TopScale, or BottomScale;
·
Qt::Vertical with NoScale, LeftScale, or RightScale.

Member Function Documentation

const QwtAbstractScaleDraw * QwtAbstractScale::abstractScaleDraw () const [protected, inherited] Returns

Scale draw

See also:

setAbstractScaleDraw()

QwtAbstractScaleDraw * QwtAbstractScale::abstractScaleDraw () [protected, inherited] Returns

Scale draw

See also:

setAbstractScaleDraw()

bool QwtAbstractScale::autoScale () const [inherited] Returns

true if autoscaling is enabled

QwtSlider::BGSTYLE QwtSlider::bgStyle () const Returns

the background style.

int QwtSlider::borderWidth () const Returns

the border width.

void QwtSlider::draw (QPainter *p, const QRect &update_rect) [protected]

Draw the QwtSlider.

void QwtSlider::drawSlider (QPainter *painter, const QRect &r) [protected, virtual] Draw the slider into the specified rectangle.

Parameters:

painter Painter
r Rectangle

void QwtSlider::drawThumb (QPainter *painter, const QRect &sliderRect, intpos) [protected, virtual] Draw the thumb at a position

Parameters:

painter Painter
sliderRect Bounding rectangle of the slider
pos Position of the slider thumb

double QwtDoubleRange::exactPrevValue () const [protected, inherited]

Returns the exact previous value.

double QwtDoubleRange::exactValue () const [protected, inherited]

Returns the exact value. The exact value is the value which QwtDoubleRange::value would return if the value were not adjusted to the step raster. It differs from the current value only if QwtDoubleRange::fitValue or QwtDoubleRange::incValue have been used before. This function is intended for internal use in derived classes.

void QwtAbstractSlider::fitValue (doublevalue) [virtual, slot, inherited]

Set the slider's value to the nearest integer multiple of the step size. Parameters:

value Value

See also:

setValue(), incValue()

Reimplemented from QwtDoubleRange.

void QwtSlider::fontChange (const QFont &oldFont) [protected, virtual]

Notify change in font.

void QwtSlider::getScrollMode (const QPoint &p, int &scrollMode, int &direction) [protected, virtual]

Determine scrolling mode and direction. Parameters:

p point
scrollMode Scrolling mode
direction Direction

Implements QwtAbstractSlider.

double QwtSlider::getValue (const QPoint &pos) [protected, virtual] Determine the value corresponding to a specified mouse location.

Parameters:

pos Mouse position

Implements QwtAbstractSlider.

void QwtDoubleRange::incPages (intnPages) [virtual, inherited]

Increment the value by a specified number of pages. Parameters:

nPages Number of pages to increment. A negative number decrements the value.

Warning:

The Page size is specified in the constructor.

void QwtAbstractSlider::incValue (intsteps) [virtual, slot, inherited]

Increment the value by a specified number of steps. Parameters:

steps number of steps

See also:

setValue()

Reimplemented from QwtDoubleRange.

bool QwtAbstractSlider::isReadOnly () const [inherited] In read only mode the slider can't be controlled by mouse or keyboard.

Returns:

true if read only

See also:

setReadOnly()

bool QwtAbstractSlider::isValid () const [inline, inherited] See also

QwtDblRange::isValid()

Reimplemented from QwtDoubleRange.

void QwtAbstractSlider::keyPressEvent (QKeyEvent *e) [protected, virtual, inherited] Handles key events

·
Key_Down, KeyLeft
Decrement by 1
·
Key_Up, Key_Right
Increment by 1

Parameters:

e Key event

See also:

isReadOnly()

Reimplemented in QwtCompass, and QwtDial.

void QwtSlider::layoutSlider (boolupdate_geometry = true) [protected] Recalculate the slider's geometry and layout based on the current rect and fonts.

Parameters:

update_geometry notify the layout system and call update to redraw the scale

double QwtAbstractSlider::mass () const [virtual, inherited] Returns

mass

See also:

setMass()

Reimplemented in QwtWheel.

double QwtDoubleRange::maxValue () const [inherited]

Returns the value of the second border of the range. maxValue returns the value which has been specified as the second parameter in QwtDoubleRange::setRange.

See also:

setRange()

QSize QwtSlider::minimumSizeHint () const [virtual]

Return a minimum size hint. Warning:

The return value of QwtSlider::minimumSizeHint() depends on the font and the scale.

double QwtDoubleRange::minValue () const [inherited]

Returns the value at the first border of the range. minValue returns the value which has been specified as the first parameter in setRange().

See also:

setRange()

void QwtAbstractSlider::mouseMoveEvent (QMouseEvent *e) [protected, virtual, inherited] Mouse Move Event handler

Parameters:

e Mouse event

void QwtAbstractSlider::mousePressEvent (QMouseEvent *e) [protected, virtual, inherited] Mouse press event handler

Parameters:

e Mouse event

void QwtAbstractSlider::mouseReleaseEvent (QMouseEvent *e) [protected, virtual, inherited] Mouse Release Event handler

Parameters:

e Mouse event

Qt::Orientation QwtAbstractSlider::orientation () const [inherited] Returns

Orientation

See also:

setOrientation()

int QwtDoubleRange::pageSize () const [inherited]

Returns the page size in steps.

void QwtSlider::paintEvent (QPaintEvent *event) [protected, virtual] Qt paint event

Parameters:

event Paint event

bool QwtDoubleRange::periodic () const [inherited]

Returns true if the range is periodic. See also:

setPeriodic()

double QwtDoubleRange::prevValue () const [protected, inherited]

Returns the previous value.

void QwtSlider::rangeChange () [protected, virtual]

Notify change of range.

Reimplemented from QwtDoubleRange.

void QwtAbstractScale::rescale (doublevmin, doublevmax, doublestepSize = 0.0) [protected, inherited] Recalculate the scale division and update the scale draw.

Parameters:

vmin Lower limit of the scale interval
vmax Upper limit of the scale interval
stepSize Major step size

See also:

scaleChange()

void QwtSlider::resizeEvent (QResizeEvent *e) [protected, virtual]

Qt resize event.

void QwtSlider::scaleChange () [protected, virtual]

Notify changed scale.

Reimplemented from QwtAbstractScale.

const QwtScaleDraw * QwtSlider::scaleDraw () const Returns

the scale draw of the slider

See also:

setScaleDraw()

QwtScaleDraw * QwtSlider::scaleDraw () [protected] Returns

the scale draw of the slider

See also:

setScaleDraw()

const QwtScaleEngine * QwtAbstractScale::scaleEngine () const [inherited] Returns

Scale engine

See also:

setScaleEngine()

QwtScaleEngine * QwtAbstractScale::scaleEngine () [inherited] Returns

Scale engine

See also:

setScaleEngine()

const QwtScaleMap & QwtAbstractScale::scaleMap () const [inherited] Returns

abstractScaleDraw()->scaleMap()

int QwtAbstractScale::scaleMaxMajor () const [inherited] Returns

Max. number of major tick intervals The default value is 5.

int QwtAbstractScale::scaleMaxMinor () const [inherited] Returns

Max. number of minor tick intervals The default value is 3.

QwtSlider::ScalePos QwtSlider::scalePosition () const

Return the scale position.

void QwtAbstractScale::setAbstractScaleDraw (QwtAbstractScaleDraw *scaleDraw) [protected, inherited]

Set a scale draw. scaleDraw has to be created with new and will be deleted in ~QwtAbstractScale or the next call of setAbstractScaleDraw.

void QwtAbstractScale::setAutoScale () [inherited]

Advise the widget to control the scale range internally. Autoscaling is on by default.

See also:

setScale(), autoScale()

void QwtSlider::setBgStyle (BGSTYLEst) Set the background style.

void QwtSlider::setBorderWidth (intbd)

Change the slider's border width. Parameters:

bd border width

void QwtSlider::setMargins (intxMargin, intyMargin)

Set distances between the widget's border and internals. Parameters:

xMargin Horizontal margin
yMargin Vertical margin

void QwtAbstractSlider::setMass (doubleval) [virtual, inherited]

Set the slider's mass for flywheel effect. If the slider's mass is greater then 0, it will continue to move after the mouse button has been released. Its speed decreases with time at a rate depending on the slider's mass. A large mass means that it will continue to move for a long time.

Derived widgets may overload this function to make it public.

Parameters:

val New mass in kg

See also:

mass()

Reimplemented in QwtWheel.

void QwtSlider::setOrientation (Qt::Orientationo) [virtual]

Set the orientation. Parameters:

o Orientation. Allowed values are Qt::Horizontal and Qt::Vertical.

If the new orientation and the old scale position are an invalid combination, the scale position will be set to QwtSlider::NoScale.

See also:

QwtAbstractSlider::orientation()

Reimplemented from QwtAbstractSlider.

void QwtDoubleRange::setPeriodic (booltf) [inherited]

Make the range periodic. When the range is periodic, the value will be set to a point inside the interval such that

point = value + n * width .fi

if the user tries to set a new value which is outside the range. If the range is nonperiodic (the default), values outside the range will be clipped.

Parameters:
tf true for a periodic range

void QwtAbstractSlider::setPosition (const QPoint &p) [protected, virtual, inherited] Move the slider to a specified point, adjust the value and emit signals if necessary.

void QwtDoubleRange::setRange (doublevmin, doublevmax, doublevstep = 0.0, intpageSize = 1) [inherited]

Specify range and step size. Parameters:

vmin lower boundary of the interval
vmax higher boundary of the interval
vstep step width
pageSize page size in steps

Warning:

·
A change of the range changes the value if it lies outside the new range. The current value will *not* be adjusted to the new step raster.
·
vmax < vmin is allowed.
·
If the step size is left out or set to zero, it will be set to 1/100 of the interval length.
·
If the step size has an absurd value, it will be corrected to a better one.

void QwtAbstractSlider::setReadOnly (boolreadOnly) [virtual, slot, inherited] En/Disable read only mode

In read only mode the slider can't be controlled by mouse or keyboard.

Parameters:

readOnly Enables in case of true

See also:

isReadOnly()

void QwtAbstractScale::setScale (const QwtDoubleInterval &interval, doublestepSize = 0.0) [inherited]

Specify a scale. Disable autoscaling and define a scale by an interval and a step size

Parameters:

interval Interval
stepSize major step size

See also:

setAutoScale()

void QwtAbstractScale::setScale (doublevmin, doublevmax, doublestepSize = 0.0) [inherited]

Specify a scale. Disable autoscaling and define a scale by an interval and a step size

Parameters:

vmin lower limit of the scale interval
vmax upper limit of the scale interval
stepSize major step size

See also:

setAutoScale()

void QwtAbstractScale::setScale (const QwtScaleDiv &scaleDiv) [inherited]

Specify a scale. Disable autoscaling and define a scale by a scale division

Parameters:

scaleDiv Scale division

See also:

setAutoScale()

void QwtSlider::setScaleDraw (QwtScaleDraw *scaleDraw)

Set a scale draw. For changing the labels of the scales, it is necessary to derive from QwtScaleDraw and overload QwtScaleDraw::label().

Parameters:

scaleDraw ScaleDraw object, that has to be created with new and will be deleted in ~QwtSlider or the next call of setScaleDraw().

void QwtAbstractScale::setScaleEngine (QwtScaleEngine *scaleEngine) [inherited]

Set a scale engine. The scale engine is responsible for calculating the scale division, and in case of auto scaling how to align the scale.

scaleEngine has to be created with new and will be deleted in ~QwtAbstractScale or the next call of setScaleEngine.

void QwtAbstractScale::setScaleMaxMajor (intticks) [inherited]

Set the maximum number of major tick intervals. The scale's major ticks are calculated automatically such that the number of major intervals does not exceed ticks. The default value is 5.

Parameters:

ticks maximal number of major ticks.

See also:

QwtAbstractScaleDraw

void QwtAbstractScale::setScaleMaxMinor (intticks) [inherited]

Set the maximum number of minor tick intervals. The scale's minor ticks are calculated automatically such that the number of minor intervals does not exceed ticks. The default value is 3.

Parameters:

ticks

See also:

QwtAbstractScaleDraw

void QwtSlider::setScalePosition (ScalePoss)

Change the scale position (and slider orientation). Parameters:

s Position of the scale.

A valid combination of scale position and orientation is enforced:

·
if the new scale position is Left or Right, the scale orientation will become Qt::Vertical;
·
if the new scale position is Bottom or Top the scale orientation will become Qt::Horizontal;
·
if the new scale position is QwtSlider::NoScale, the scale orientation will not change.

void QwtDoubleRange::setStep (doublevstep) [inherited]

Change the step raster. Parameters:

vstep new step width

Warning:

The value will not be adjusted to the new step raster.

Reimplemented in QwtCounter.

void QwtSlider::setThumbLength (intthumbLength)

Set the slider's thumb length. Parameters:

thumbLength new length

void QwtSlider::setThumbWidth (intw)

Change the width of the thumb. Parameters:

w new width

void QwtAbstractSlider::setTracking (boolenable) [inherited]

Enables or disables tracking. If tracking is enabled, the slider emits a valueChanged() signal whenever its value changes (the default behaviour). If tracking is disabled, the value changed() signal will only be emitted if:

·
the user releases the mouse button and the value has changed or
·
at the end of automatic scrolling.

Tracking is enabled by default.

Parameters:

enable true (enable) or false (disable) tracking.

void QwtAbstractSlider::setUpdateTime (intt) [inherited]

Specify the update interval for automatic scrolling. Parameters:

t update interval in milliseconds

See also:

getScrollMode()

void QwtAbstractSlider::setValid (boolvalid) [inline, inherited] Parameters

valid true/false

See also:

QwtDblRange::isValid()

Reimplemented from QwtDoubleRange.

void QwtAbstractSlider::setValue (doubleval) [virtual, slot, inherited]

Move the slider to a specified value. This function can be used to move the slider to a value which is not an integer multiple of the step size.

Parameters:

val new value

See also:

fitValue()

Reimplemented from QwtDoubleRange.

QSize QwtSlider::sizeHint () const [virtual] Returns

QwtSlider::minimumSizeHint()

void QwtAbstractSlider::sliderMoved (doublevalue) [signal, inherited] This signal is emitted when the user moves the slider with the mouse.

Parameters:

value new value

void QwtAbstractSlider::sliderPressed () [signal, inherited] This signal is emitted when the user presses the movable part of the slider (start ScrMouse Mode).

void QwtAbstractSlider::sliderReleased () [signal, inherited] This signal is emitted when the user releases the movable part of the slider.

double QwtDoubleRange::step () const [inherited] Returns

the step size

See also:

setStep(), setRange()

Reimplemented in QwtCounter.

void QwtDoubleRange::stepChange () [protected, virtual, inherited]

Notify a change of the step size. This virtual function is called whenever the step size changes. The default implementation does nothing.

void QwtAbstractSlider::stopMoving () [inherited]

Stop updating if automatic scrolling is active.

int QwtSlider::thumbLength () const Returns

the thumb length.

int QwtSlider::thumbWidth () const Returns

the thumb width.

void QwtAbstractSlider::timerEvent (QTimerEvent *e) [protected, virtual, inherited] Qt timer event

Parameters:

e Timer event

double QwtDoubleRange::value () const [inherited]

Returns the current value.

Reimplemented in QwtCounter.

void QwtSlider::valueChange () [protected, virtual]

Notify change of value.

Reimplemented from QwtAbstractSlider.

void QwtAbstractSlider::valueChanged (doublevalue) [signal, inherited]

Notify a change of value. In the default setting (tracking enabled), this signal will be emitted every time the value changes ( see setTracking() ).

Parameters:

value new value

void QwtAbstractSlider::wheelEvent (QWheelEvent *e) [protected, virtual, inherited] Wheel Event handler

Parameters:

e Whell event

int QwtSlider::xyPosition (doublevalue) const [protected] Find the x/y position for a given value v

Parameters:

value Value

Author

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Mon Aug 1 2011 Version 5.2.2 Qwt User's Guide